<!--<input #phone placeholder="phone number" />-->
<input class="form-control" ref-phone placeholder="phone number" />
<button class="btn btn-primary" (click)="callPhone(phone.value)">Call</button>


<p>引用组件：</p>
<button class="btn btn-primary" (click)="sizer.inc()">inc</button>
<app-sizer [(size)]="fontSize" #sizer></app-sizer>
fontSize: {{ fontSize }}
